package com.bzhang.springcloud.com.bzhang.springcloud.bl;

import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * @author ：Bin.Z
 * @description：
 * @date ：2022/6/27 15:52
 */
@Component
@Slf4j
public class MyLB implements LoadBalancer{

    private AtomicInteger atomicInteger = new AtomicInteger(0);

    //坐标
    private final int getAndIncrement(){
        int current;
        int next;
        do{
            current = this.atomicInteger.get();
            next = current >= 2147483647 ? 0 : current+1;
            log.info("next:"+next);
        }while (!this.atomicInteger.compareAndSet(current,next)); //第一个参数是期望值，第二个参数是修改值是
        return next;
    }
    @Override
    public ServiceInstance instances(List<ServiceInstance> serviceInstances) { //得到机器的列表
        int index = this.getAndIncrement() % serviceInstances.size();//得到服务器的下标位置
            return serviceInstances.get(index);
    }
}
